* {
  margin: 0;
  padding: 0;
}

html,
body {
  width: 100%;
  height: 100%;
  font-family: '楷体';
}

body {
  background-color: #DCDFE6;
}

div {
  width: 300px;
  height: 300px;
  border-radius: 50%;
  margin: 100px auto;
  background: url(img/pic-1.jpg) no-repeat center;
  position: relative;
  cursor: pointer;
}

div p {
  width: 280px;
  height: 280px;
  border-radius: 50%;
  border: 10px solid #F56C6C;
  border-top-color: #67C23A;
  border-left-color: #67C23A;
  /* CSS过度 */
  background-color: rgba(0, 0, 0, 0);
  transition-property: transform, background-color;
  transition-duration: 2s, 2s;
}

div:hover p {
  transform: rotate(180deg);
  /* CSS动画 */
  background-color: rgba(0, 0, 0, .6);
}

div h1 {
  color: white;
  font-size: 48px;
  position: absolute;
  /* 子绝对定位，父相对定位 */
  top: 0;
  left: 0;
  width: 300px;
  height: 300px;
  text-align: center;
  line-height: 300px;
  display: none;
  transition: all 1s linear;
}

div:hover h1 {
  display: block;
}